<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    .multi{
        width: 200px;
        height: 300px;
        background-image: url(./透明底图片.jpg),url(./th.jpg);
        background-position: top left, top left; 
        background-repeat: no-repeat, no-repeat; 
        background-size: cover, cover;
    }
    .gradient{
        width: 300px;
        height: 100px;
        background: linear-gradient(to right, blue, red);
    }
    .sticky{
        width: 800px;
        height: 1000px;
        background-image: url(./OIP-C.jpg);
        background-position: bottom center; 
        background-repeat: no-repeat;
        background-size: cover; 
        background-attachment: fixed;
    }
    .cropped{
       width: 400px;
       height: 400px;
       background-image: url(./透明底图片.jpg);
       background-position: center center;
       background-repeat: no-repeat;
       background-color: black;
    }
    .responsive{
        width: 450px;
        height: 500px;
        background-image: url(./OIP-C.jpg);
        background-repeat: no-repeat;
        background-position: center;
        background-size: cover;
    }
</style>
<body>
    <div class="multi"></div>
    <div class="gradient"></div>
    <div class="sticky"></div>
    <div class="cropped"></div>
    <div class="responsive"></div>
</body>
</html>